properties of soil

1. TITLE: PROPERTIES OF SOIL
PRESENTED BY:
AMIR RASOOL TANTRAY
UNDER THE GUIDANCE OF:
ASSISTANT PROFFESSOR KAVYA P GOWDA,EPCET,BANGALORE

2. ABSTRACT
•Design of the various pavement layers is very much dependent on the strength of the sub
grade soil over which they are going to be laid.
•Sub grade strength is also depending on the basic properties of the soil. Sub grade
strength is mostly expressed in terms of CBR (California Bearing Ratio).
• Weaker sub grade essentially requires thicker layers whereas stronger sub grade goes
well with thinner pavement layers.
The pavement and the sub grade mutually must sustain the traffic volume .
•The sub grade is always subjected to change in its moisture content due to rainfall,
capillary action, overflow or rise of water table.
• This project is an attempt to understand the basic properties of sub grade such as specific
gravity, Atterberg limits ,particle size distribution, optimum moisture content , maximum
dry density, UCC and permeability test.

3. INTRODUCTION
• A pavement is a durable surface having materials laid down on an area subjected to
sustain mainly the vehicular traffic, such as a road or highway.
• A pavement is typically a structure of various layers resting over soil either in
embankment or in cutting.
• A pavement is classified in general in two categories, i.e. namely a flexible pavement and
a rigid pavement.
• Traditionally the design of either kind of pavement is based on the strength of the
compacted soil in the pavement, called sub grade.
• The design of the pavement layers laid over the sub grade soil starts off with the
determination of sub grade strength and the traffic volume which is to be carried.
• The design of pavement is very much dependent on the sub grade strength of soil.
Design criteria mainly needs thickness of layers.
• Weaker sub grade needs thicker layers whereas stronger sub grade needs thinner
pavement layers.

4. Objectives
To increase the bearing capacity.
To reduce permeability of soil.
To design flexible pavement.
Cost analysis.
To reduce the thickness of pavement

5. TESTS AND METHODOLOGY
•GRAIN SIZE ANALYSIS: IS 2720(PART 4) 1985
•SPECIFIC GRAVITY: IS 2720 (PART 3)1980
•ATTERBERG LIMITS: IS 2720(PART 5)1985
• MODIFIED COMPACTION TEST:IS 2720(PART 8)1983
•UCC : IS 2720(PART 10)1991
•PERMEABILITY: IS 2720(PART 17)1986
•CBR: IS 2720(PART 16)1986

6. 1) SIEVE ANALYSIS
Sieve analysis is the name given to the operation of dividing a sample of
aggregate into various fractions each consisting of particles of the same size. The
sieve analysis is conducted to determine the particle size distribution in a
sample of aggregate, which we call gradation. The sieve analysis gives us a
detailed idea regarding the type, consistency and components of the soil.
From the graph Cu=D60/D10=8 & Cc = D30^2/ D10*D60 =2.3
2) ATTERBERG LIMITS
BRIEF STEPS INVOLVED IN THE EXPERIMENTS
.Plastic Limit:
This limit lies between the plastic and semi-solid state of the soil. It is
determined by rolling out a thread of the soil on a flat surface which is non-
porous. It is the minimum water content at which the soil just begins to
crumble while rolling into a thread of approximately 3mm diameter. Plastic
limit is denoted by wP.

7. Liquid Limit:
It is the water content of the soil between the liquid state and plastic state of the soil. It
can be defined as the minimum water content at which the soil, though in liquid state,
shows small shearing strength against flowing. It is measured by the Casagrande’s
apparatus and is denoted by Wl. Liquid limit corresponding to25 blows =35%
3) Specific gravity
Specific gravity of a substance denotes the number of times that substance is heavier
than water. In simpler words we can define it as the ratio between the mass of any
substance of a definite volume divided by mass of equal volume of water. In case of
soils, specific gravity is the number of times the soil solids are heavier than equal volume
of water. Different types of soil have different specific gravities, general range for specific
gravity of soils:
1 SAND 2.63 - 2.67
2 SILT 2.65 - 2.7
3 CLAY AND SILTY CLAY 2.67 - 2.9
4 ORGANIC SOILS <2.0
Specific Gravity Classification

8. TRIAL 1 2 3
NO OF BLOWS 17 35 30
Wt OF EMPTY CONTAINER 21.2 20 15.4
Wt OF CONTAINER+DRY SOIL 40 28 34.8
Wt OF CONTAINER +DRY SOIL 34.4 26 29.6
WATER CONTENT 42.4 33.3 36.6
BLOWS WC
17 42.4
35 33.3
30 36.6
LIQUID LIMIT READINGS

9. 1
10
100
0 5 10 15 20 25 30 35 40
WATERCONTENT
NO OF BLOWS
LIQUID LIMT CORRESPONDING TO 25 BLOWS =35%
LIQUID LIMIT GRAPH

10. 4. Particle Size Distribution
•The distribution of particles of different sizes determines many physical properties of the
soil such as its strength, permeability, density etc.
•Particle size distribution is found out by two methods, first is sieve analysis and the other
method is sedimentation analysis
•Both are followed by plotting the results on a semi-log graph. The percentage finer N as
the ordinate and the particle diameter i.e. sieve size as the abscissa on a logarithmic scale.
•The curve generated from the result gives us an idea of the type and gradation of the
soil.
• If the curve is higher up or is more towards the left, it means that the soil has more
representation from the finer particles; if it is towards the right, we can deduce that the
soil has more of the coarse grained particles.
• The soil may be of two types- well graded or poorly graded (uniformly graded). Well
graded soils have particles from all the size ranges in a good amount.

11. sieve
size(mm)
mass
retained Retained %
cumulative
wt. cumulative % % finer
4.75 0.00 0.00 0.00 0.00 100.00
2.36 40.20 8.00 40.20 8.00 92.00
1.18 84.06 16.74 124.26 24.74 75.26
0.6 90.20 17.96 214.46 42.70 57.30
0.3 106.40 21.19 320.86 63.89 36.11
0.15 108.80 21.66 429.66 85.56 14.44
0.075 59.40 11.83 489.06 97.38 2.62
sum 8.70 1.73 497.76 99.12 0.88
WET SIEVE ANALYSIS

12. 0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
0.010.1110
%finer
sieve size(mm)
wet sieve analysis

13. 4. Shear strength
Shearing stresses are induced in a loaded soil and when these stresses reach their
limiting value, deformation starts in the soil which leads to failure of the soil mass. The
shear strength of a soil is its resistance to the deformation caused by the shear stresses
acting on the loaded soil. The shear strength of a soil is one of the most important
characteristics. The experiment used to determine the strength is Unconfined
Compression test.
ENGINEERING PROPERTIES OF SOIL
SOIL PROPERTIES VALUES
Specific gravity (Gs) 2.65
Consistency limit
Liquid limit 43%
PLASTIC LIMIT 21%
PLASTICITY INDEX 22
USCS CLASSIFICATION MH
GRAIN SIZE ANALYSIS
GRAVEL 0%
SAND 0%
SILT 86%
CLAY 14%

14. MODIFIED COMPACTION TEST
•This experiment gives a clear relationship between the dry density of the
soil and the moisture content of the soil.
• The experimental setup consists of (i) cylindrical metal mould (ii)
detachable base plate, (iii) collar (iv) rammer (4.5KG) .
• Compaction process helps in increasing the bulk density by driving out the
air from the voids
•The maximum dry density (MDD) is achieved when the soil is compacted at
relatively high moisture content and almost all the air is driven out, this
moisture content is called optimum moisture content (OMC).
• After plotting the data from the experiment with water content as the
abscissa and dry density as the ordinate, we can obtain the OMC and MDD

15. Unconfined compression test
•This experiment is used to determine the unconfined
compressive strength of the soil sample which in turn is used to
calculate the unconsolidated, undrained shear strength of
unconfined soil.
•The unconfined compressive strength (qu) is the compressive
stress at which the unconfined cylindrical soil sample fails under
simple compressive test.
•The experimental setup constitutes of the compression device
and dial gauges for load and deformation.
•The load was taken for different readings of strain dial gauge
starting from ε = 0.005 and increasing by 0.005 at each step.
•The corrected cross-sectional area was calculated by dividing the
area by (1- ε) and then the compressive stress for each step was
calculated by dividing the load with the corrected area.

16. Empty wt of Mould (M1gms) 5576 5576 5576 5576 5576 5576
Weight of mould + compacted
soil(W2)gm 9073.4 9343.5 6563.8 9924.6 9763.5 9645.3
Weight of Compacted Soil
(W3)gm 3497.4 3767.5 3987.8 4348.6 4187.5 4069.3
Bulk Density (M3/V)g/cm3) 1.58 1.7 1.8 1.96 1.89 1.84
Water Content (w)% 8 10 12 14 16 18
Dry Density (ρb/1+w)gm/cm3 1.46 1.54 1.6 1.72 1.63 1.56
WATER CONTENT DRY DENSITY
8 1.46
10 1.54
12 1.6
14 1.72
16 1.63
18 1.56
MODIFIED COMPACTION TEST

17. 1.4
1.45
1.5
1.55
1.6
1.65
1.7
1.75
0 2 4 6 8 10 12 14 16 18 20
DRYDENSITY
WATER CONTENT
FROM THE GRAPH IT IS EVIDENT THAT
OMC=14%
MDD=1.72 g/cc
OMC CURVE

18. DGR
(divisions) Deformation(mm) PRR (divisions) Load (KN)
Corrected
Area (mm2) Strain Stress
0 0 0 0 0 0 0
50 0.5 2 0.07 9.677 0.0588 0.0007233
100 1 5 0.0175 9.734 0.1176 0.001797
150 105 9 0.0315 9.792 0.176 0.003217
200 2 10 0.035 9.831 0.235 0.00356
250 2.5 14 0.049 9.911 0.302 0.00492
300 3 14 0.049 9.972 0.383 0.00584
350 3.5 24 0.084 10.033 0.402 0.00612
400 4 27 0.0945 10.095 0.465 0.00784
450 4.5 29 0.1015 10.157 0.529 0.00902
500 5 31 0.1085 10.221 0.5882 0.0106
550 5.5 30 0.1 10.285 0.647 0.00972
AVERAGE UCS VALUE @ 0TH DAY

19. 0
0.002
0.004
0.006
0.008
0.01
0.012
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
STRAIN
STRESS
UCS=0.0192KN/M2
UCS @0TH DAY (AVERAGE VALUE)

20. DGR
(divisions) Deformation(mm)
PRR
(divisions) Load (KN)
Corrected Area
(mm2) Strain Stress
0 0 0 0 0 0 0
50 0.5 18 0.063 9.67 0.0588 0.01256
100 1 25 0.0875 9.734 0.1176 0.0298
150 1.5 28 0.098 9.792 0.176 0.03489
200 2 33 0.1155 9.851 0.235 0.03668
250 2.5 37 0.1295 9.911 0.294 0.03789
300 3 35 0.147 9.972 0.353 0.03485
350 3.5 32 0.152 10.033 0.4109 0.03187
AVERAGE UCS VALUE @ 3RD DAY

21. 0
0.005
0.01
0.015
0.02
0.025
0.03
0.035
0.04
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45
Stress
Strain
ucs=0.03755kn/m2
UCS @ 3rd day (AVERAGE VALUE)

22. Deformation(mm) PRR (divisions) Load (KN)
Corrected Area
(mm2) Strain
Stress
(KN/M3)
0 0 0 0 0 0
0.5 7 0.025 9.677 0.0588 0.03
1 18 0.063 9.734 0.1176 0.07
1.5 23 0.08 9.792 0.146 0.08
2 26 0.091 9.851 0.235 0.09
2.5 26 0.091 9.911 0.276 0.0984
3 26 0.091 9.972 0.353 0.0921
3.5 24 0.091 10.033 0.3812 0.08
UCS @ 7TH DAY (AVERAGE VALUE)

23. 0
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
0.009
0 0.1 0.2 0.3 0.4 0.5 0.6
Stress
Strain
UCS =0.0756KN/M2
UCS @7th day (AVERAGE VALUE)

24. References
1. S.K Khanna and C.E.G Justo, Highway engineering.
2. G.Venkatappa Rao, RS Sasidar, Solid Waste Management and Engineered
Landfills
3. Hoover, J.M., Meoller, D.T., Pitt, J.M. Smith, S.G. and Wainaina, N.W. (1982)
“Performance of randomly oriented fibre reinforced Roadways Soils”, Lowa DOT
Project-HR-211, Department of Transportation, Highway Division, Lowa State
University.
4. Orman, M.E. (1994) “Interface shear strength properties of roughened HDP
Journal of Geotechnical Engineering, ASCE, 120(4), 758-761.
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“Proceeding, 5th International Conference on Ground Improvement Technique,
Kaulalumpur, Malaysia, 321-328.
6. HMSO. (1952) “Soil Mechanics for Road Engineers” London
7. Madhavi Vedula, Pawan Nath G and Prof. B. P. Chandrashekar , NRRDA, New
Delhi Critical review of innovative rural road construction techniques and their
impacts.